1. Field of the Invention
The present invention relates to an ac generator having a plurality of U-shaped conductor segments that are connected to form a stator winding.
2. Description of the Related Art
A rotary electric machine having an armature winding which is comprised of a plurality of U-shaped conductor segments. Each conductor segment has a U-shaped head and a pair of legs and is coated with an insulation layer.
U.S. Pat. Nos. 5,211,670 and 5,266,858 disclose a method of manufacturing such an armature winding. Each leg is inserted into one of a plurality of slots from one end of an armature core. Thereafter, leg ends of the conductor segments are connected to one another at the other end of the armature core to form the stator winding.
In manufacturing the conductor segments, a rotating disk having a bend core and a pin is provided. The bend core is formed at the center of a rotating disk to be fitted to the inner periphery of the U-shaped head of the conductor segment. A straight conductor wire is put between the outer periphery of the bend core and the pin, and, then, the disk is rotated in a certain angle to bend the wire along the outer periphery of the bend core.
However, the above manufacturing method causes the U-shaped head to incline to one of the legs, and the head has to be reshaped in order to form a coil end of the armature winding. This is an obstacle to productivity of the armature winding, and the reshaping of the conductor segments may cause insulation failure.